Colour tunability by optically induced electron transfer in diarylamine-dibenzothiophene derivatives

Three arylamino-dibenzothiophene derivatives (Ary2-DBT, Ary2-DBTSO and Ary2-DBTSO2), based on a molecular architecture D-& pi;-D, have been designed and synthesized. The three compounds, showing different oxidation states of the S-heterocycle (sulfide, sulfoxide and sulfone), have been studied in order to investigate the effects of both the neutral and radical species on the photophysical properties. To this purpose, cyclic voltammetry, UV/Vis-NIR and fluorescence spectroscopy, TDDFT calculation, and EPR spectroscopy measurements were performed. Moreover, spectroelectrochemical measurements have demonstrated the ability of these molecular systems to shift their colour output by following a change in the applied voltage. Finally, as a proof of concept, electrochromic devices have been fabricated to demonstrate the functionality of these dyes as anodic components.